I don't get the Theory of Relativity

[nitsuj]

Over the years I've learned that knowing or understanding the theory of relativity isn't really all that important.

oh my land!

Of course it's important!

How else would someone know/understand relativity?

 

[wild999711]

I hope this is not straying from the topic, but what class is general relativity usually taught in? I've had special relativity in modern physics and I have to agree it was very special at first...my brain was total mush because I kept missing the point of one important sentence.

Normally there aren't classes on it till Grad school, and yeah special relativity is much easier with 4 vectors than the methods presented in modern physics classes.

 

[harrylin]

Why does everyone always pick on relativity theory?

Good point - I was going to answer that it may be due to the air of "magic" that is given to relativity, but the same is true for QM... perhaps it is because nobody really understands QM?

 

[Kholdstare]

Good point - I was going to answer that it may be due to the air of "magic" that is given to relativity, but the same is true for QM... perhaps it is because nobody really understands QM?

QM and G(S)R are not understandable concepts to begin with. The way we understand things cannot be applied to understand them. They were discovered as some rules, and they will stay that way.

 

[harrylin]

QM and G(S)R are not understandable concepts to begin with. The way we understand things cannot be applied to understand them. They were discovered as some rules, and they will stay that way.

Then why do you think is SR/GR more popular as claimed to be "not understandable" than QM? Once more: I propose that in particular SR is generally more frustrating as many people cannot make sense of it despite its simple math. And being confronted with explanations by people who have no problem with it (despite your contrary claim) may increase that frustration.

 

[Kholdstare]

Then why do you think is SR/GR more popular as claimed to be "not understandable" than QM? Once more: I propose that in particular SR is generally more frustrating as many people cannot make sense of it despite its simple math. And being confronted with explanations by people who have no problem with it (despite your contrary claim) may increase that frustration.

Because that's pop-sci culture and over-sensationalized. Think of an example. In a hypothetical case if I push a button in a country an explosion occurs in other country. Now with further investigation it was seen that there's nothing else to be found about the phenomena. There's no connection, no cause-effect relationship, just nothing. Now, how will you explain them or understand them? You try to imagine similar situations and correlate them with the wired phenomena. It does not guarantee they are actually what is happening. Gives a sense of satisfaction, but never assures anyone. What happens actually? Honestly nobody knows.

 

[Jimmy Snyder]

Then why do you think is SR/GR more popular as claimed to be "not understandable" than QM? Once more: I propose that in particular SR is generally more frustrating as many people cannot make sense of it despite its simple math. And being confronted with explanations by people who have no problem with it (despite your contrary claim) may increase that frustration.

I disagree. SR is hard to believe, not hard to understand. The speed of light is constant.

 

[jgens]

QM and G(S)R are not understandable concepts to begin with. The way we understand things cannot be applied to understand them. They were discovered as some rules, and they will stay that way.

I disagree with this, especially concerning SR. If we taught Euclidean geometry the same way we teach SR, by focusing on coordinate dependent quantities rather than invariant quantities, then the subject would be equally as confusing; in fact, there are even versions of the twin paradox, length contraction, time dilation, etc. in Euclidean geometry. The geometry of spacetime assumed in SR is not all that far off of the Euclidean geometry assumed in Newtonian mechanics. Sure there are a few pieces of our intuition that have to be fixed, but it's really not as weird as people make it out to be.

 

[Vorde]

I agree with the recent posts and not the comment saying QM/GR/SR is inherently unbelievable and impossible to understand.

SR makes perfect rational sense once you accept a postulate which seems contrary to everyday experience - that's the initial trouble, after that point everything makes sense.

Likewise with GR once you accept some of the tenets which seem to be against common sense then the whole thing beings to make sense.

QM is the same, it's just that the rule you have to accept which goes against common sense - the quantitization of nature - is further from our everyday experience than anything else.

 

[Jimmy Snyder]

SR makes perfect rational sense once you accept a postulate which seems contrary to everyday experience.

That's precisely what I meant by 'hard to believe.'

 

[harrylin]

I disagree. SR is hard to believe, not hard to understand. The speed of light is constant.

For me SR is both understandable (although it took me a while, I have to admit - I really had to dig in the literature!) and as a result I now find it also easy to believe; I did find a way to make (common) sense of it.
[Edit: Note that the two postulates (the original ones*, not those of textbooks) are both on purpose common-sense postulates - the trouble was in understanding how they can both be true.]

In contrast, QM (especially combined with Bell's theorem) results in a Big Mystery that remains a source of heavy debate; there seems to be no interpretation possible that matches common sense (at least my personal common sense, and that of many others). My purpose of joining PF was that hopefully one of the discussions here will one day provide a possible answer that makes sense to me.

*http://www.fourmilab.ch/etexts/einstein/specrel/www/

 

[Vorde]

In contrast, QM (especially combined with Bell's theorem) results in a Big Mystery that remains a source of heavy debate; there seems to be no interpretation possible that matches common sense (at least my personal common sense, and that of many others). My purpose of joining PF was that hopefully one of the discussions here will one day provide a possible answer that makes sense to me.

I'd say the reason QM is so confusing is that there is no way to reconcile it with common sense.